Update use of nova config to work with folsom
Update use of nova config to work with folsom

The configuration API for nova changed between folsom and
grizzly. This change uses the folsom API if necessary,
allowing the trunk version of ceilometer to continue to
work with folsom.

Change-Id: Ib59649ed6c04ea7218efa245dea428e0db4a16d0
Signed-off-by: Doug Hellmann <8c845c26a3868dadec615703cd974244eb2ac6d1@dreamhost.com>

openstack/ceilometer,MisterPup/Ceilometer-Juno-Extension,ityaptin/ceilometer,r-mibu/ceilometer,NeCTAR-RC/ceilometer,isyippee/ceilometer,maestro-hybrid-cloud/ceilometer,redhat-openstack/ceilometer,citrix-openstack-build/ceilometer,cernops/ceilometer,ityaptin/ceilometer,mathslinux/ceilometer,shootstar/ctest,idegtiarov/ceilometer,Juniper/ceilometer,tanglei528/ceilometer,idegtiarov/ceilometer,NeCTAR-RC/ceilometer,rackerlabs/instrumented-ceilometer,citrix-openstack-build/ceilometer,froyobin/ceilometer,fabian4/ceilometer,rickerc/ceilometer_audit,NeCTAR-RC/ceilometer,pczerkas/aodh,mathslinux/ceilometer,openstack/ceilometer,rickerc/ceilometer_audit,r-mibu/ceilometer,froyobin/ceilometer,fabian4/ceilometer,cernops/ceilometer,citrix-openstack-build/ceilometer,maestro-hybrid-cloud/ceilometer,tanglei528/ceilometer,sileht/aodh,rackerlabs/instrumented-ceilometer,luogangyi/Ceilometer-oVirt,eayunstack/ceilometer,m1093782566/openstack_org_ceilometer,dreamhost/ceilometer,MisterPup/Ceilometer-Juno-Extension,sileht/aodh,rackerlabs/instrumented-ceilometer,rickerc/ceilometer_audit,JioCloud/ceilometer,pkilambi/ceilometer,chungg/aodh,tanglei528/ceilometer,dreamhost/ceilometer,pkilambi/ceilometer,isyippee/ceilometer,chungg/aodh,redhat-openstack/ceilometer,JioCloud/ceilometer,JioCloud/ceilometer,openstack/aodh,openstack/aodh,Juniper/ceilometer,luogangyi/Ceilometer-oVirt,shootstar/ctest,eayunstack/ceilometer,m1093782566/openstack_org_ceilometer,pczerkas/aodh